1. Technical Field PA1 2. Description of the Prior Art
This invention relates to cordless telephones and more particularly to a cordless telephone arranged for deployment in a public telephone system.
Telephone communications in public areas has traditionally been limited to a person using a public telephone where he or she could make either charge calls, pay calls or credit card calls. The mobility of the user has thus been limited to the immediate surroundings of the public telephone, as determined by the length of the telephone handset cord. One alternative to this limited mobility in telephone or two-way voice communications is to utilize a portable cellular telephone. With such a telephone, the user is able to freely move about while engaging in voice communications with a called party. Cellular telephones and cellular telephone service are fairly expensive to date, however. Cellular telephones are designed to be employed in a system which requires, among other things, a considerable investment in switching gear for transferring calls. Because of costs considerations, therefore, portable cellular telephones are unattractive to many potential users of portable communications equipment.
Another alternative to the public telephone that provides mobility in two-way voice communications in public areas is the new Telepoint System that has been provided for use in Europe. This system employs time-division duplex transmissions between a portable telephone and a base unit for providing cordless telephone communications. Like the cellular telephone, this telephone and its associated system is costly due to system requirements and the necessary circuit complexity required in the telephone for operation in such a system.
While the foregoing systems provide mobility in two-way voice communications in public areas, it is desirable to have a cordless telephone suitable for operation in a system that is not unduly complicated or expensive to implement in order to provide both mobility and service at reasonable cost for users of portable communications equipment.